/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright (c) 1997-2010 Oracle and/or its affiliates. All rights reserved.
 *
 * The contents of this file are subject to the terms of either the GNU
 * General Public License Version 2 only ("GPL") or the Common Development
 * and Distribution License("CDDL") (collectively, the "License").  You
 * may not use this file except in compliance with the License.  You can
 * obtain a copy of the License at
 * https://glassfish.dev.java.net/public/CDDL+GPL_1_1.html
 * or packager/legal/LICENSE.txt.  See the License for the specific
 * language governing permissions and limitations under the License.
 *
 * When distributing the software, include this License Header Notice in each
 * file and include the License file at packager/legal/LICENSE.txt.
 *
 * GPL Classpath Exception:
 * Oracle designates this particular file as subject to the "Classpath"
 * exception as provided by Oracle in the GPL Version 2 section of the License
 * file that accompanied this code.
 *
 * Modifications:
 * If applicable, add the following below the License Header, with the fields
 * enclosed by brackets [] replaced by your own identifying information:
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 * If you wish your version of this file to be governed by only the CDDL or
 * only the GPL Version 2, indicate your decision by adding "[Contributor]
 * elects to include this software in this distribution under the [CDDL or GPL
 * Version 2] license."  If you don't indicate a single choice of license, a
 * recipient has the option to distribute your version of this file under
 * either the CDDL, the GPL Version 2 or to extend the choice of license to
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 */

package com.sun.mail.util;

import java.io.*;

/**
 * Convert lines into the canonical format, that is, terminate lines with the
 * CRLF sequence.
 * 
 * @author John Mani
 */
public class CRLFOutputStream extends FilterOutputStream {
	protected int lastb = -1;
	protected boolean atBOL = true; // at beginning of line?
	private static final byte[] newline = { (byte) '\r', (byte) '\n' };

	public CRLFOutputStream(OutputStream os) {
		super(os);
	}

	public void write(int b) throws IOException {
		if (b == '\r') {
			writeln();
		} else if (b == '\n') {
			if (lastb != '\r')
				writeln();
		} else {
			out.write(b);
			atBOL = false;
		}
		lastb = b;
	}

	public void write(byte b[]) throws IOException {
		write(b, 0, b.length);
	}

	public void write(byte b[], int off, int len) throws IOException {
		int start = off;

		len += off;
		for (int i = start; i < len; i++) {
			if (b[i] == '\r') {
				out.write(b, start, i - start);
				writeln();
				start = i + 1;
			} else if (b[i] == '\n') {
				if (lastb != '\r') {
					out.write(b, start, i - start);
					writeln();
				}
				start = i + 1;
			}
			lastb = b[i];
		}
		if ((len - start) > 0) {
			out.write(b, start, len - start);
			atBOL = false;
		}
	}

	/*
	 * Just write out a new line, something similar to out.println()
	 */
	public void writeln() throws IOException {
		out.write(newline);
		atBOL = true;
	}
}
